Systematic and objective wet-lab testing of instruments for phacoemulsification: new Formalin Quadrant Model
Christina Giger-Lange1, Karin Rattenbacher-Kiser, Jessica Di Lanzo
1From the Institute of Medical Engineering, Lucerne University of Applied Sciences and Arts, Lucerne, Switzerland (Giger-Lange, Rattenbacher-Kiser, Di Lanzo, Di Nardo, Ille); Departement of Ophthalmologie, Medical University of Vienna, Vienna, Austria (Menapace).
Journal of Cataract and Refractive Surgery
|October 10, 2023
Summary
A new Formalin Quadrant Model allows objective testing of phacoemulsification instruments. This validated wet-lab model efficiently simulates cataract densities, enabling rapid instrument evaluation before clinical trials.
Area of Science:
- Ophthalmology
- Biomedical Engineering
- Surgical Instrumentation
Background:
- Phacoemulsification is a key cataract surgery technique.
- Objective and systematic efficiency testing of surgical instruments is crucial for innovation.
- Existing methods may lack reproducibility or require extensive surgical expertise.
Purpose of the Study:
- To validate an improved wet-lab model for systematic and objective efficiency testing of phacoemulsification instruments.
- To establish a reproducible method for simulating various cataract densities.
Main Methods:
- Porcine lenses were incubated in formalin to simulate hard, middle-hard, and soft cataracts.
- Lenses were emulsified in a silicone test chamber using controlled ultrasound energy.
- Efficiency was measured by effective phacoemulsification time, liquid consumption, and total surgery time.
Main Results:
- Formalin incubation times were validated for different cataract densities (2h, 1.25h, 0.5h).
- The model allowed testing by non-surgical staff, yielding fast and reproducible results.
- Higher fluidics settings correlated with reduced effective phacoemulsification time, shorter surgery duration, and lower liquid consumption.
Conclusions:
- The Formalin Quadrant Model provides a validated, efficient, and reproducible method for testing phacoemulsification instrumentation.
- It accurately represents the clinical situation, enabling profound instrument improvement before clinical trials.
- This model facilitates the development and optimization of new surgical tools.
Related Concept Videos
01:12Modeling and Similitude
Scaled modeling is a fundamental technique in engineering, enabling the study of large and complex systems by creating smaller, manageable replicas that recreate critical characteristics of the original. In hydrology and civil infrastructure, for example, scaled models of dams help analyze water flow, turbulence, and pressure. This method allows for accurate predictions of real-world behavior within a controlled environment, significantly reducing the cost and time involved in full-scale...
01:30Typical Model Studies
Fluid mechanics model studies often utilize scaled-down systems to predict fluid behavior in full-scale environments, such as river flows, dam spillways, and structures interacting with open surfaces. Maintaining Froude number similarity in river models is crucial, as it replicates surface flow features like wave patterns and velocities.